DATA DETAILS

August 31, 2007 to August 21, 2009:

This anemometer tower was borrowed from the Western Area Power Authority (WAPA) under WAPA’s anemometer loan program.. It was installed above Fowler on the shoulders of the Arkansas River valley on August 31, 2007 and removed on August 21, 2009.

All data was collected using an NRG #40 Anemometer and NRG #200 Wind Vane mounted on a tilt-up tower at a height of 20m. This equipment fed into an NRG Wind Explorer data logger. All data plugs were sent into the Wind Powering America program for analysis. All data plug files and text versions of these files are given below.

It is important to note that the temperature was not recorded during this period.

Using this data, an analysis of the wind resource report was developed using Windographer 1.45. For this report, a validation analysis was performed on the data. This data was filtered two ways:

Any wind speed data where the wind speed was less than 1 mph for 3 hours or more was deleted.

Any wind direction data where the wind direction varied by less than 3 degrees over 6 hours was deleted

Windographer was then used to add in synthetic data to these intervals with suspect data. The combined data files (with and without the validation analysis), and the Windographer files (with and without the validation analysis) are given below:

Note: The wind power density and wind power class at 50m are projections of the data from 20m. A surface roughness of 0.1 meters was assumed for this projection. This is the surface roughness for an area with a few trees. This value was then used this to calculate the roughness class and the power law exponent shown above.

Standard deviation (mph)

7.322

Frequency of calms (%)

0

Total data elements

311,334

Suspect/missing elements

3,717

Data completeness (%)

98.8

Windographer was used to match up the wind at this site with the performance curves of some common turbines of various sizes and various heights, allowing for losses of about 18%. The table below shows the results. For the larger turbines, the tower height was increased to account for the larger turbine blades - the wind resource was extrapolated to these higher heights. Keep in mind that the larger and the higher the turbine, the better the wind and the greater the output. But of course, as the tower heights and turbine sizes increase so does the cost.